<template>
    请输入姓名：<input type="text" v-model="username">
    <div>姓名是：{{ username }}</div>
    <input type="text" v-model.number="n1">+<input type="text" v-model.number="n2">={{n1+n2}}
</template>
<script setup>
import {ref} from 'vue';
const username=ref('zhangsan')
const n1=ref(1)
const n2 = ref(2)
</script>